So this was the oil change I was really looking forward to. As you may or may not know, I run AMSOIL Signature Series oil in this car. AMSOIL claims you can run 25,000 mile intervals between oil changes, or 15,000 mile intervals under severe use. I decided to test their claims, but since I autocross and whatnot, I decided to play it safe and go with a moderate 10,000 mile interval. That is still significantly higher than the 6,000 mile interval dictated by Subaru.
In any event, the first 10,000 mile change test results seemed good, but there were still some elevated levels of various minerals due to the engine still being broken in. With this oil change, I was really hoping to see these levels drop further, and get confirmation that the 10,000 mile intervals weren’t harming the engine. Well, it seems that this is exactly what I got! The test results are attached below, but here’s the summary they included:
“It doesn’t look like the 10,000-mile run or the autocross use is disagreeing with this BRZ. In fact, iron, copper, and silicon are a lot lower than last time, showing that the last of the wear-in stuff is washing out. You might see silicon drop a bit more next time, but even if it doesn’t this level is fine. The TBN is strong again at 5.1, so there’s lots of active additive left for a longer run next time. No excess fuel or moisture is present. Try 11,500 miles on the next oil. This is shaping up to be a really nice engine for you.”
